Cliffside caves in the former kingdom of Mustang are giving up their secrets.

Photograph by Cory Richards

Climbers and scientists follow a trail above the Kali Gandaki River in Nepal’s remote Mustang region. More than 60 feet above are rows of unexplored man-made caves dug centuries ago. There may be thousands in the region.

To reach a series of caves dug into a cliff 155 feet above the valley floor, Matt Segal scales a rock face so fragile it often breaks off to the touch. Linked by a ledge, the 800-year-old caves, empty now, may once have stored manuscripts.

In the private chapel of a home in the city of Lo Manthang, a Tibetan Buddhist lama performs a rite with cymbals, drum, and incense. Once part of greater Tibet, Mustang remains suffused with Tibetan culture.

A lama holds a mala, or Tibetan rosary, used to keep track of prayers and mantras in a ritual to foretell the future. He follows the religion of Bon, which predated Buddhism in ancient Tibet and is still practiced in a few areas of Mustang.

Tsewang Tashi, a Tibetan Buddhist lama, leads his horse through the village of Samdzong, near the Chinese border. During a turbulent era 800 years ago, residents likely took refuge in caves, returning to the village generations later, after the region stabilized. “One good place to live, if you’re worried about your neighbors, is in caves,” says archaeologist Mark Aldenderfer.

Yandu Bista, 53, warms herself at a fire in a cave chamber that was once her home in the northern Mustang village of Garphu. Born in this cave, Bista also gave birth to a daughter here 11 years ago and later moved with her family into town. “I like living in a cave better,” she says. “In winter it was warm and nice. But water was difficult to bring up here. Firewood, too.” In Garphu many people have used the existing caves as the basis for their homes, says archaeologist Mark Aldenderfer. “There are a number of rooms already. You don’t need to build a new house, but simply put up a facade in front of it.”

Ted Hesser enters a maze of rooms in a looted cave near Chuksang. Originally used as burial chambers, these caves became primarily living quarters around a thousand years ago. By the 15th century most people had moved into traditional villages.

Walkie-talkie in one hand and human jawbone in the other, expedition leader Pete Athans picks his way through a looted mortuary cave while Segal surveys a pit from which robbers tossed bones. Scientists hope that DNA from teeth will help pinpoint the origins of the bodies.

Small multicolored glass beads were attached to a cloth hood fastened to the gold-and-silver death mask found in Samdzong’s Tomb 5. Although archaeologists know of no local beadmaking tradition in Mustang, more than a thousand beads dating from A.D. 300 to 700 have been found there. They originated from areas including modern-day Pakistan, Iran, and southern India, “and were certainly traded into the region,” says Aldenderfer. “We do not know, of course, what they were traded for.”

A death mask, some 1,500 years old and made of gold and silver, covered the face of an adult male found in a coffin inside a Samdzong cave, called Tomb 5 by researchers. Centuries ago in this region, masks were commonly placed on the elite dead.

An infant and an adult female’s foot (next photo) were among the naturally mummified remains of 30 people discovered in a mortuary cliff cave at Mustang’s Mebrak site in 1995 by German and Nepalese archaeologists.

Dusk falls over the temples and homes of Tsarang, once the region’s most important town. In Mustang, where the centuries have not disrupted the traditional rhythm of life, the caves offer clues to a time when the remote Himalayan kingdom was a hub linking Tibet to the rest of the world.